I had my 60th last week, held a party in a curry house with all the musicians I've gigged with in the last 10 years. Naturally there was a 2-hour jam session once the curry was all gone. Some pretty decent musicians present, too.
The only non-middle-aged people there were my two kids plus three of their friends, all five of them aged 21 - 28.
We were playing exactly what you'd expect us to play, and none of it was aimed at the yoof market, but the five youngsters were blown away by it all. They hardly ever check out live music unless it's at a big festival that they can boast about to their friends afterwards. They'd all forgotten about, or had never actually known about, the buzz and the pleasure to be derived from yer actual, live music.